Methods and systems for selectively delivering different types of bi-ventricular pacing

Abstract

Baseline BiV pacing is delivered and a corresponding baseline BiV efficacy score is determined. Intrinsic AV conduction is allowed and an intrinsic AV conduction interval is determined. BiV fusion pacing is delivered and a corresponding efficacy score is determined, for each of a plurality of different paced AV delays, each determined based on the intrinsic AV conduction interval and a different negative hysteresis delta. The baseline BiV pacing is selected for delivery during a period of time if the baseline BiV efficacy score is better than all of the efficacy scores. BiV fusion pacing is selected for delivery during the period of time, using one of the plurality of different paced AV delays for which a corresponding efficacy score was determined, if the efficacy score corresponding to at least one of the plurality of different paced AV delays is better than the baseline BiV efficacy score.

What is claimed is: 
     
       1. A method for selectively delivering different types of bi-ventricular (BiV) pacing, comprising:
 (a) delivering baseline BiV pacing for a plurality of cardiac cycles and determining a corresponding baseline BiV efficacy score, wherein a predetermined atrioventricular (AV) delay is used for the baseline BiV pacing; 
 (b) allowing for intrinsic AV conduction for a plurality of cardiac cycles and determining an intrinsic AV conduction interval and a corresponding intrinsic AV conduction efficacy score; 
 (c) delivering BiV fusion pacing for a plurality of cardiac cycles and determining a corresponding negative AV hysteresis (NAVH) efficacy score, for each of a plurality of different paced AV delays, wherein each of the plurality of different paced AV delays is determined based on the intrinsic AV conduction interval and a different negative hysteresis delta; 
 (d) based on results of steps (a), (b), and (c), either allowing for intrinsic AV conduction for a period of time, selecting and delivering the baseline BiV pacing for the period of time, or selecting and delivering BiV fusion pacing for the period of time using one of the plurality of different paced AV delays for which the corresponding NAVH efficacy score was determined. 
 
     
     
       2. The method of  claim 1 , further comprising:
 determining whether at least one premature ventricular contraction (PVC) occurs while the baseline BiV pacing is being delivered, or while the BiV fusion pacing is being delivered; and 
 in response to determining that the at least one PVC occurs while the baseline BiV pacing is being delivered, the corresponding baseline BiV efficacy score is determined in a manner that is unaffected by the at least one PVC that occurs while the baseline BiV pacing is being delivered; or 
 in response to determining that the at least one PVC occurs while the BiV fusion pacing is being delivered, determining at least one of the corresponding NAVH efficacy scores in a manner that is unaffected by the at least one PVC that occurs while the BiV fusion pacing is being delivered. 
 
     
     
       3. The method of  claim 1 , comprising wherein step (d) comprises:
 allowing for intrinsic AV conduction for the period of time in response to determining that the intrinsic AV conduction efficacy score is better than the baseline BiV efficacy score and better than all of the NAVH efficacy scores determined for the plurality of different paced AV delays; 
 selecting and delivering the baseline BiV pacing for the period of time in response to determining that the baseline BiV efficacy score is better than the intrinsic AV conduction efficacy score and all of the NAVH efficacy scores determined for the plurality of different paced AV delays used during the BiV fusion pacing; or 
 selecting and delivering BiV fusion pacing for the period of time, using one of the plurality of different paced AV delays for which the corresponding NAVH efficacy score was determined, in response to determining that the NAVH efficacy score corresponding to at least one of the plurality of different paced AV delays used during the BiV fusion pacing is better than the baseline BiV efficacy score and the intrinsic AV conduction efficacy score. 
 
     
     
       4. The method of  claim 1 , wherein each of the plurality of different paced AV delays is determined by subtracting a different negative hysteresis delta from the intrinsic AV conduction interval. 
     
     
       5. The method of  claim 1 , wherein step (d) includes determining whether the intrinsic AV conduction efficacy score is better than the baseline BiV efficacy score and better than all of the NAVH efficacy scores determined for the plurality of different paced AV delays, whether the baseline BiV efficacy score is better than the intrinsic AV conduction efficacy score and all of the NAVH efficacy scores determined for the plurality of different paced AV delays, or whether the NAVH efficacy score corresponding to at least one of the plurality of different paced AV delays is better than the intrinsic AV conduction efficacy score and the baseline BiV efficacy score. 
     
     
       6. The method of  claim 1 , wherein steps (a), (b), (c), and (d) are repeated from time to time and include:
 at a first point in time, determining that the baseline BiV efficacy score is better than all of the NAVH efficacy scores determined for the plurality of different paced AV delays used during the BiV fusion pacing, and in response thereto, the selecting and delivering at step (d) comprises selecting and delivering the baseline BiV pacing for a first period of time; 
 at a second point in time, determining that the NAVH efficacy score corresponding to at least one of the plurality of different paced AV delays used during the BiV fusion pacing is better than the baseline BiV efficacy score, and in response thereto, the selecting and delivering at step (d) comprises selecting and delivering BiV fusion pacing for a second period of time using one of the plurality of different paced AV delays for which the corresponding efficacy score was determined to be better than the baseline BiV efficacy score; and 
 at a third point in time, determining that the intrinsic AV conduction efficacy score is better than the baseline BiV efficacy score and better than all of the NAVH efficacy scores determined for the plurality of different paced AV delays used during the BiV fusion pacing, and in response thereto, at step (d) comprises allowing for intrinsic AV conduction for a third period of time. 
 
     
     
       7. The method of  claim 1 , further comprising:
 determining whether at least one premature ventricular contraction (PVC) occurs while the baseline BiV pacing is being delivered, while allowing for intrinsic AV conduction, and while the BiV fusion pacing is being delivered; and at least one of the following 
 in response to determining that the at least one PVC occurs while the baseline BiV pacing is being delivered, the corresponding baseline BiV efficacy score is determined in a manner that is unaffected by the at least one PVC that occurs while the baseline BiV pacing is being delivered; 
 in response to determining that the at least one PVC occurs while allowing for intrinsic AV conduction, the corresponding intrinsic AV conduction efficacy score is determined in a manner that is unaffected by the at least one PVC that occurs while allowing for intrinsic AV conduction; or 
 in response to determining that the at least one PVC occurs while the BiV fusion pacing is being delivered, at least one of the corresponding NAVH efficacy scores is determined in a manner that is unaffected by the at least one PVC that occurs while the BiV fusion pacing is being delivered. 
 
     
     
       8. The method of  claim 1 , further comprising:
 for each of a plurality of different sets of BiV pacing parameters, using a sensor implanted in a pulmonary artery to obtain a corresponding measure of pulmonary artery pressure (PAP), and using one or more implanted electrodes to detect a QRS complex corresponding to each measure of PAP; 
 identifying which of the measures of PAP is a best one of the measures of PAP; and 
 saving, as a preferred QRS complex template, the detected QRS complex that corresponds to the best one of the measures of PAP; 
 wherein the determining the intrinsic AV conduction efficacy score includes determining a measure of similarity between a QRS complex obtained while allowing intrinsic AV conduction and the saved preferred QRS complex template; 
 wherein the determining the baseline BiV efficacy score includes determining a measure of similarity between a QRS complex obtained while delivering the baseline BiV pacing and the saved preferred QRS complex template; and 
 wherein the determining the corresponding efficacy, for each of the plurality of different paced AV delays, includes determining a corresponding measure of similarity between a QRS complex obtained while pacing using one of the different paced AV delays and the saved preferred QRS complex template. 
 
     
     
       9. The method of  claim 8 , wherein:
 the identifying which of the measures of PAP is the best one of the measures of PAP comprised identifying which of the measures of PAP is lowest; and 
 the saving, as the preferred QRS complex template, the detected QRS complex that corresponds to the best one of the measures of PAP, comprises saving, as the preferred QRS complex template, the detected QRS complex that corresponds to the measure of PAP that is the lowest. 
 
     
     
       10. The method of  claim 1 , wherein:
 each efficacy score is based on at least one of QRS width or QRS morphology. 
 
     
     
       11. A system, comprising:
 a first lead comprising at least one electrode configured to be implanted in a left ventricle; 
 a second lead comprising at least one electrode configured to be implanted in a right ventricle; 
 at least one pulse generator each of which is coupleable to at least one of the first and second leads and each of which is configured to deliver cardiac stimulation pulses to pacing sites using at least one of the electrodes; 
 at least one sensing circuit each of which is configured to obtain at least one signal indicative of electrical activity of a patient's heart; 
 at least one processor for use in specifying an atrioventricular (AV) pacing delay used for bi-ventricular (BiV) pacing and specifying which of the electrodes are used for pacing; 
 wherein the system is configured to use the leads, the at least one pulse generator, the at least one sensing circuit, and the at least one processor, to
 deliver baseline BiV pacing for a plurality of cardiac cycles and determine a corresponding baseline BiV efficacy score, wherein a predetermined AV delay is used for the baseline BiV pacing; 
 allow for intrinsic AV conduction for a plurality of cardiac cycles and determine an intrinsic AV conduction interval and a corresponding intrinsic AV conduction efficacy score; 
 deliver BiV fusion pacing for a plurality of cardiac cycles and determine a corresponding negative AV hysteresis (NAVH) efficacy score, for each of a plurality of different paced AV delays, wherein each of the plurality of different paced AV delays is determined based on the intrinsic AV conduction interval and a different negative hysteresis delta; 
 select and deliver baseline BiV pacing for a period of time if the baseline BiV efficacy score is better than the intrinsic AV conduction score and all of the NAVH efficacy scores corresponding the plurality of different paced AV delays used during the BiV fusion pacing; 
 select and deliver BiV fusion pacing for the period of time, using one of the plurality of different paced AV delays for which a corresponding NAVH efficacy score was determined, if the NAVH efficacy score corresponding to at least one of the plurality of different paced AV delays used during the BiV fusion pacing is better than the baseline BiV efficacy score and the intrinsic AV conduction score; and 
 allow for intrinsic AV conduction for the period of time, if the intrinsic AV conduction efficacy score is better than the baseline BiV efficacy score and better than all of the NAVH efficacy scores determined for the plurality of different paced AV delays used during the BiV fusion pacing. 
 
 
     
     
       12. The system of  claim 11 , wherein the at least one processor is also configured to:
 determine whether at least one premature ventricular contraction (PVC) occurs while the baseline BiV pacing is being delivered, while allowing for intrinsic AV conduction, or while the BiV fusion pacing is being delivered; and 
 in response to determining that the at least one PVC occurs while the baseline BiV pacing is being delivered, determine the corresponding baseline BiV efficacy score in a manner that is unaffected by the at least one PVC that occurs while the baseline BiV pacing is being delivered; 
 in response to determining that the at least one PVC occurs while allowing for intrinsic AV conduction, determine the intrinsic AV conduction interval in a manner that is unaffected by the at least one PVC that occurs while allowing for intrinsic AV conduction; or 
 in response to determining that the at least one PVC occurs while the BiV fusion pacing is being delivered, determine at least one of the corresponding NAVH efficacy scores in a manner that is unaffected by the at least one PVC that occurs while the BiV fusion pacing is being delivered. 
 
     
     
       13. The system of  claim 11 , further comprising:
 a sensor configured to be implanted in a pulmonary artery; and 
 wherein the at least one processor is also configured to
 determine the corresponding intrinsic AV conduction efficacy score by using the sensor to obtain a corresponding measure of pulmonary artery pressure (PAP) while allowing for intrinsic AV conduction; 
 determine the corresponding baseline BiV efficacy score by using the sensor to obtain a corresponding measure of PAP while baseline BiV pacing is being delivered; and 
 determine the corresponding NAVH efficacy score, for each of the plurality of different paced AV delays, by using the sensor to obtain a corresponding measure of PAP for each of the plurality of different paced AV delays. 
 
 
     
     
       14. The system of  claim 11 , further comprising:
 a sensor configured to be implanted in a pulmonary artery; and 
 wherein the system is also configured to use the leads, the at least one pulse generator, the at least one sensing circuit, the at least one processor, and the sensor to
 obtain a corresponding measure of pulmonary artery pressure (PAP), and detect a QRS complex corresponding to each measure of PAP, for each of a plurality of different sets of BiV pacing parameters; 
 identify which of the measures of PAP is a best one of the measures of PAP; and 
 save, as a preferred QRS complex template, the detected QRS complex that corresponds to the best one of the measures of PAP; and 
 
 wherein the at least one processor is also configured to
 determine the baseline BiV efficacy score by determining a measure of similarity between a QRS complex obtained while the baseline BiV pacing is being delivered and the saved preferred QRS complex template; 
 determine the corresponding NAVH efficacy score, for each of the plurality of different paced AV delays, by determining a corresponding measure of similarity between a QRS complex obtained while pacing using one of the different paced AV delays and the saved preferred QRS complex template; and 
 determine the intrinsic AV conduction efficacy score by determining a measure of similarity between a QRS complex obtained while allowing intrinsic AV conduction and the saved preferred QRS complex template. 
 
 
     
     
       15. The system of  claim 14 , wherein the at least one processor is configured to:
 identify a lowest one of the measures of PAP as the best one of the measures of PAP; and 
 save, as the preferred QRS complex template, the detected QRS complex that corresponds to the lowest one of the measures of PAP. 
 
     
     
       16. The system of  claim 11 , wherein:
 each efficacy score is based on at least one of QRS width or QRS morphology. 
 
     
     
       17. The system of  claim 11 , wherein that at least one processor is configured to ensure that none of the paced AV delays exceed a specified maximum allowed AV delay. 
     
     
       18. The system of  claim 11 , wherein at least one of the different negative hysteresis deltas, used to determine the plurality of different paced AV delays, is stored in memory of the system. 
     
     
       19. The system of  claim 11 , wherein the different negative hysteresis deltas are between ten and one hundred twenty milliseconds. 
     
     
       20. The method of  claim 2 , wherein a said efficacy score is determined in a manner that is unaffected by the at least one PVC by ignoring or excluding a measurement, used to determine the said efficacy score, that is associated with at least one cardiac cycle in which the at least one PVC occurs.